Groundwater - Surfacewater Intermixing Model and Recharge Conditions in Delhi Area as Derived from δ18O and δD

1996 ◽  
pp. 103-117
Author(s):  
P. S. Datta ◽  
S. K. Tyagi
Keyword(s):  
Δ18o And Δd

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

Relative humidity history on the Batang–Litang Plateau of western China since 1755 reconstructed from tree-ring δ18O and δD

2013 ◽  
Vol 42 (9-10) ◽  
pp. 2639-2654 ◽  
Author(s):  
Wenling An ◽  
Xiaohong Liu ◽  
Steven W. Leavitt ◽  
Guobao Xu ◽  
Xiaomin Zeng ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Tree Ring ◽  
Western China ◽  
Δ18o And Δd

Climatic interpretation of δ18O and δD in tree rings (reply)

Nature ◽  
1978 ◽  
Vol 271 (5640) ◽  
pp. 93-93 ◽  
Author(s):  
A. T. WILSON
Keyword(s):  
Tree Rings ◽  
Δ18o And Δd

Implications of variations in δ18O and δD in precipitation at Madoi in the eastern Tibetan Plateau

2013 ◽  
Vol 313-314 ◽  
pp. 56-61 ◽  
Author(s):  
Wei Ren ◽  
Tandong Yao ◽  
Xiaoxin Yang ◽  
Daniel R. Joswiak
Keyword(s):  
Tibetan Plateau ◽  
Eastern Tibetan Plateau ◽  
Δ18o And Δd

scholarly journals The Effects of Temperature on the Turnover of δ18O and δD in Juvenile Corn Snakes (Elaphe guttata): A Novel Study with Ecological Implications

Diversity ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 19
Author(s):  
Samuel Hirt ◽  
Kent Hatch
Keyword(s):  
Stable Isotope ◽  
Analysis Of Covariance ◽  
Environmental Research ◽  
Treatment Groups ◽  
University Of Utah ◽  
Effects Of Temperature ◽  
C 30 ◽  
Δ18o And Δd ◽  
Elaphe Guttata ◽  
Δd And Δ18o

The use of natural variation in stable isotope ratios continues to be used in ecological studies without proper validation through laboratory studies. This study tested the effects of temperature, time, and turnover in the scales of juvenile corn snakes (Elaphe guttata) in a controlled, laboratory environment. Snakes were assigned to four treatment groups (24 °C, 27 °C, 30 °C, and freely thermoregulating), and one snake from each group was sacrificed weekly. Scales from each snake were washed, dried, and analyzed for δD and δ18O at the Stable Isotope Research Facility for Environmental Research at the University of Utah. The effects of temperature on the turnover of tissues was only significant when comparing the thermoregulating group to the pooled treatment groups (24 °C, 27 °C, and 30 °C) in the δ18O of scales (p = 0.006). After normalizing data on the δD and δ18O using percent change for comparison, δ18O appeared to be turning over at a faster rate than δD as indicated by an analysis of covariance (ANCOVA) test for homogeneity of slopes (F1,53 = 69.7, p < 0.001). With further testing of assumptions, a modification of our methods could provide information on the composition of drinking water sources in a species that switches between two isotopically distinct sources, such as during seasonal shifts in habitat or migration, and/or estimates of long-term field metabolic rates based on the turnover of these isotopes.

scholarly journals An Endorheic Lake in a Changing Climate: Geochemical Investigations at Lake Trasimeno (Italy)

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1319 ◽  
Author(s):  
Frondini ◽  
Dragoni ◽  
Morgantini ◽  
Donnini ◽  
Cardellini ◽  
...  
Keyword(s):  
Lake Water ◽  
Land Surface ◽  
Western Europe ◽  
Central Italy ◽  
Surface Air Temperature ◽  
Strong Increase ◽  
Precipitation Regime ◽  
Mobile Species ◽  
Δ18o And Δd ◽  
Endorheic Lake

Lake Trasimeno is a shallow, endorheic lake located in central Italy. It is the fourth Italian largest lake and is one of the largest endorheic basins in western Europe. Because of its shallow depth and the absence of natural outflows, the lake, in historical times, alternated from periods of floods to strong decreases of the water level during periods of prolonged drought. Lake water is characterised by a NaCl composition and relatively high salinity. The geochemical and isotopic monitoring of lake water from 2006 to 2018 shows the presence of well-defined seasonal trends, strictly correlated to precipitation regime and evaporation. These trends are clearly highlighted by the isotopic composition of lake water (δ18O and δD) and by the variations of dissolved mobile species. In the long term, a progressive warming of lake water and a strong increase of total dissolved inorganic solids have been observed, indicating Lake Trasimeno as a paradigmatic example of how climate change can cause large variations of water quality and quantity. Furthermore, the rate of variation of lake water temperature is very close to the rate of variation of land-surface air temperature, LSAT, suggesting that shallow endorheic lakes can be used as a proxy for global warming measurements.

scholarly journals Spatial variation of stable isotopic composition in surface waters of the Huai River basin, China and the regional hydrological implication

2017 ◽  
Vol 49 (5) ◽  
pp. 1452-1466 ◽  
Author(s):  
Liang Zhang ◽  
Ruiqiang Yuan ◽  
Xianfang Song ◽  
Jun Xia
Keyword(s):  
River Basin ◽  
Surface Waters ◽  
Large Scale ◽  
Eastern China ◽  
Lower Latitude ◽  
Huai River Basin ◽  
Study Results ◽  
Huai River ◽  
Δ18o And Δd ◽  
The Huai River Basin

Abstract Oxygen (δ18O) and hydrogen (δD) stable isotopes in the surface waters of the Huai River basin were analyzed in this study. Results indicated the northern waters had higher δ18O and δD than the southern waters, the water δ18O and δD increased along the water flow directions. These variations mostly resulted from the spatial differences of precipitation and evaporation. Comparing with published different continents' river water δ18O data, this study suggests that evaporation effect is a more plausible interpretation than altitude effect as the cause of δ18O increasing from upriver to downriver waters. This region's local surface water line (LSWL, δD = 5.36δ18O − 18.39; r2 = 0.84) represents one of the first presented LSWLs in eastern China. The correlation between d-excess and δ18O demonstrates this region is dominated by the Pacific oceanic moisture masses in summer. Comparing the various LSWLs from eastern China and eastern United States river waters, this study proposes a hypothesis that the water LSWLs slopes of lower latitude regions may be less than those of higher latitude regions within similar topographic areas. This hypothesis may be tested in other geographically comparable coupled areas in the world if corresponding large-scale data can be found.

scholarly journals Water isotopic ratios from a continuously melted ice core sample

2011 ◽  
Vol 4 (11) ◽  
pp. 2531-2542 ◽  
Author(s):  
V. Gkinis ◽  
T. J. Popp ◽  
T. Blunier ◽  
M. Bigler ◽  
S. Schüpbach ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Water ◽  
Ice Core ◽  
Flow Analysis ◽  
Water Concentration ◽  
Isotopic Analysis ◽  
Fused Silica ◽  
Chemical Components ◽  
Smoothing Effects ◽  
Δ18o And Δd

Abstract. A new technique for on-line high resolution isotopic analysis of liquid water, tailored for ice core studies is presented. We built an interface between a Wavelength Scanned Cavity Ring Down Spectrometer (WS-CRDS) purchased from Picarro Inc. and a Continuous Flow Analysis (CFA) system. The system offers the possibility to perform simultaneuous water isotopic analysis of δ18O and δD on a continuous stream of liquid water as generated from a continuously melted ice rod. Injection of sub μl amounts of liquid water is achieved by pumping sample through a fused silica capillary and instantaneously vaporizing it with 100% efficiency in a~home made oven at a temperature of 170 °C. A calibration procedure allows for proper reporting of the data on the VSMOW–SLAP scale. We apply the necessary corrections based on the assessed performance of the system regarding instrumental drifts and dependance on the water concentration in the optical cavity. The melt rates are monitored in order to assign a depth scale to the measured isotopic profiles. Application of spectral methods yields the combined uncertainty of the system at below 0.1‰ and 0.5‰ for δ18O and δD, respectively. This performance is comparable to that achieved with mass spectrometry. Dispersion of the sample in the transfer lines limits the temporal resolution of the technique. In this work we investigate and assess these dispersion effects. By using an optimal filtering method we show how the measured profiles can be corrected for the smoothing effects resulting from the sample dispersion. Considering the significant advantages the technique offers, i.e. simultaneuous measurement of δ18O and δD, potentially in combination with chemical components that are traditionally measured on CFA systems, notable reduction on analysis time and power consumption, we consider it as an alternative to traditional isotope ratio mass spectrometry with the possibility to be deployed for field ice core studies. We present data acquired in the field during the 2010 season as part of the NEEM deep ice core drilling project in North Greenland.

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